When I am sitting at a light or idling my car smells very bad of exhaust/gas fumes. It did this slightly after i installed my oil catch can but its been months since then and i recently noticed it has gotten way worse. the smell doesn't occur when i have the air recirculating and/or have the ac on. the smell will also go away almost instantly after i start moving (im assuming because of air flow). also, it doesn't seem to be affecting my gas mileage except by maybe 1 mpg. im wondering if anyone else has had this problem and if there are any suggestions as to what may be causing this. a friend said i was running to rich, but what would cause this? could one of the hoses involved in the occ have become undone? i clamped them down. if it became unattached would it cause this smell? could there be a leak affecting a vacuum seal somewhere that would cause this? what could this be? it's been on my shoulders for a while now, making me not want to do anything else to my mini, including installing the sc pulley i got for my birthday. i need to get this fixed, input is greatly appreciated. thank you

 

Which method of the oil catch can install did you follow?

 

i did it https://www.northamericanmotoring.co...an-how-to.html that way. apparantly not the most highly recommended way

could this be my problem? a leak in a hose somewhere? i have no idea...

 

That is the problem. You are putting some additional pressure into the valve cover and this is causing the smell. The PCV valve isn't working properly unless it is connected to the grey line.

You need to connect the catch can to the grey high vacuum hose under the IC only, don't bother with the low vacuum line that goes to the throttle body intake hose.

 

alright i'll try this. can you point me to a thread with the directions i need to do it this way? im so worried after i put everything back together that the hoses arent clamped enough and will come undone... also, i have the silicon type alta OCC... someone told me its possible it will collapse... is this is valid concern? i shortened it so it would fit behind the cowel and it is attached to my STB. i used clamps to make sure it was all sealed well. Thanks!

 

Here ya go.......https://www.northamericanmotoring.co...18-post26.html

Call up Alta and see if they can send you a section of pipe to stiffen up the inside of the can or you could just go get a short piece of plastic pipe to keep the can from collapsing.

 

awesome, thankyou for all your help!

 

 

update: before re routing my occ i tried replacing the fittings to the viewing tube since they seemed loose. the smell seems to be MOSTLY gone... it'll start smelling a little at 2/10 stoplights as opposed to horrible gas fumes every time im idling. it also feels less sluggish. should i just look for more leaks to cure the whole problem? when i talked to alta they basically told me that re routing a different way would be bad and all the people on here are crazy. but are they crazy for giving the directions they give with their occ?

 

Alta is way off base if they are suggesting that the referenced routing method linked to above as being incorrect. That is the only safe method of installing a catch can.

You will probably always have a bit of a smell with the Alta catch can. I don't think the silicone has the same performance as a metal can will with regards to the smell. You can get an Ebay can for $40-50 and use some decent rubber heater core hose for a very nice install.

 

I've noticed exhaust fumes in the cabin as well. Typically it happens when I'm backing out of the garage or a parking space.

I have an M7 Aluminum catch can hooked up like the second method in this thread. I've sniffed around under the hood with the engine idling and didn't notice any exhaust smells so I don't think the OCC is a factor.

I suspect that fumes are coming back through the air pressure relief vent located at the back of the boot. Has anybody else experienced this?